基于日期的星期数

Question

I need to make week number based on given date.

Today 28-08-18
Week .....

        30-07-18    1
        06-08-18    2
        13-08-18    3
        20-08-18    4
        27-08-18    5
        03-09-18    6
        10-09-18    7
        17-09-18    8
        24-09-18    9
        01-10-18    10
        08-10-18    11
        15-10-18    12
        22-10-18    13
        29-10-18    14

I want the cell next to "week" to be based on today's date.

Answer 1

• Start by inserting a date in any cell, that will be the first week.
• Create a function that calculates the difference between its adjacent cell and the first and divides it by 7. Voilà you've got the week number. You can round it if you want.

The formula is as follows: Floor((First date - Current date)/7).

Useful link for subtraction: http://www.theexceladdict.com/_t/t040303.htm .

Good luck, Alex

Answer 2

Assuming 30-07-18 is located @ A1. in B1, type in :

=WEEKNUM(A1,2)-WEEKNUM($A$1,2)+1

and drag it down. Glad that you'd tried. ( :

All the best.

Answer 3

Your base date (BD) may not be the start of the week (SOW), so the general solution could be

1. calculate the SOW from your base date: SOW = BD - WEEKDAY(BD)+2
2. calculate the distance DI from given date (GD) to SOW : DI = GD - SOW
3. convert distance into weeknumber W = INT(DI/7)

EDIT:

SOW = IF(WEEKDAY(BD)=1;BD-6;BD-WEEKDAY(BD)+2)

this is to cover cases where BD is a Sunday and SOW should be the Monday before (not after)